Accessories and signalling devices
0 of 4 hands-on
01 Introduction
Beyond the basic kit are a few small items that matter a great deal on the day something goes wrong. Most are light and cheap. This lesson covers the common ones and how to carry them well.
Objectives
- Name the common accessories divers carry and what each is for
- Explain how surface marker buoys, whistles and lights help others find a diver
- Describe how to carry accessories so that they stay secure and do not damage the reef
02 Watch
Small things that help
4 min · Video in production
- 1
A diver launching a bright surface marker buoy from depth, with the line unwinding from a reel.
- 2
A boat crew spotting the buoy from a distance, in choppy water.
- 3
A diver at the surface blowing a whistle and raising an arm.
- 4
A diver clipping a light and a cutting tool to the harness so that nothing dangles.
03 Learn
Signalling devices
A diver at the surface can be very hard to see. Waves hide a head, and a boat crew may be looking in the wrong place. Signalling devices make a diver easier to spot and to hear.
| Device | How it helps | Notes |
|---|---|---|
| Surface marker buoy (SMB) | A tall, brightly coloured inflatable tube on a line that shows where the diver is | Often sent up from depth on a reel or spool. Tells boats to keep clear and shows the group's position |
| Whistle | A loud sound that carries further than a voice | Attached to the BCD within easy reach |
| Audible signal | A device that makes a loud sound, sometimes powered by gas from the BCD | Carries a long way over water |
| Signalling mirror | Reflects sunlight to attract attention | Works in bright conditions |
| Light or strobe | Visible at night and in low light | Useful for night dives and for being seen at the surface at dusk |
| Personal locator beacon | Sends a distress signal with a position | Used on remote trips and by experienced divers. Needs registering and proper use |
Predict first
You surface some distance from the boat in a choppy sea. What helps the crew find you fastest?
Cutting tools
Fishing line and nets can entangle a diver. Many divers carry a small knife or line cutter, or shears, so that they can free themselves or a buddy. A tool should be small, secure and easy to reach with either hand. Rules about carrying knives differ in some places, and some marine parks do not allow them, so check before you go.
Lights
A torch is not only for night. Colour fades with depth, and a light shows true colours and lets you see into crevices. It also helps you signal to a buddy. Carry a light at night, in low visibility, and on dives that go into shaded areas. Check the batteries, and make sure it cannot turn on by accident in a bag.
Slates and pencils
A slate lets you write short messages to a buddy. It is simple and reliable when hand signals are not enough.
Carrying accessories
- Clip items to D-rings on the BCD with short, secure clips, so that they do not dangle.
- Use pockets for small items, and close them.
- Keep your whistle and a cutting tool where you can reach them easily with either hand.
- Do not carry too many things. Every accessory is one more thing to catch, lose or look after.
- Check that everything is secure before you enter the water.
Take a guess first
A surface marker buoy is about 1.5 m tall. A boat is 150 m away. How many times further away is the boat than the height of the marker?
04 Explore
Try it yourself
Match each device with its purpose.
Match each device with its purpose.
- Surface marker buoy
- Whistle
- Cutting tool
- Light
- Slate
05 Apply
Scenario
You and your buddy have just surfaced after a drift dive. The current has carried you a long way, and the boat is nowhere near. Waves are high. You have a surface marker buoy, a whistle and a light, and your buddy looks worried.
What should you do first?
06 Check
07 Summary
Key points
- Signalling devices such as markers, whistles, lights and mirrors help others find a diver.
- Cutting tools help with entanglement. Check local rules about carrying them.
- Lights show colour and crevices, and slates carry messages.
- Carry accessories clipped and secure, and learn to use them with an instructor.
Before you apply this in the water
- Have I been trained by a qualified instructor for this?
- Am I medically fit to dive?
- Do I have a buddy and a plan?
- Am I diving within my training and limits?
Answer every question in the Check section to mark this lesson complete.